1990 Ford Mustang GT Twin-Turbo - Hairdryer Hatchback

Two Turbos, Eight Years, And Still Counting...

Dale Amy

June 1, 2006

Photos By:
Tom Rounds

For Mark Strollo, an enjoyable and educational project-which has so far spanned more than eight years-started off with a 35,000-mile, used '90 GT. By our math, he was 16 at the time of purchase. Utterly stock "right down to the distributor cap and mufflers" and refrigerator-white, the then 7-year-old hatchback had at some point endured the childish, petulant insult of being keyed down both flanks and having its taillights kicked in. So it needed paint, but Mark didn't care. "I had yellow on the mind." A striking few coats of Chrome Yellow fixed that problem, and Mark added a few bolt-ons and was content for a while. But we all know his GT wouldn't be displayed here if that contentment had continued.

Power. The inevitable search for it originally led Mark to a Powerdyne centrifugal supercharger, but around 2001 he made the momentous decision to "go turbo." Those of you who have made a similar decision for a street 5.0 fully realize that-while turbos are a powerful, proven, and reliable commodity-the reality of good-fitting, good-running, comprehensive street turbo kits has proven somewhat evasive, as evidenced by the number of companies that tried to produce them, only to fold their tents in short order. But Mark wasn't worried. "My family has owned its own towing and recovery business for more than 50 years, so I grew up with a wrench in my hands."

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Armed with mechanical self-confidence, he acquired a Turbo Driven Concepts Stage 2XX kit shortly before the company closed its doors. Despite the kit vendor's demise, Mark managed to get the twin-turbo setup-based around quick-spooling Turbonetics T3/4 hybrid hairdryers-installed, but was plagued with exhaust and down-pipe leaks and rattles. Having previously retained Miller Race Cars to craft a nicely integrated rollcage into his GT, Mark turned once again to the Wallingford, Connecticut, firm to fabricate all new cold-side ducting, down pipes, and exhaust-all custom routed around the car's QA1 tubular K-member and A-arms. No more leaks and no more rattles, but Mark's next problem was how to tune the combo for street reliability and driveability. This rather lengthy experiment-first with the factory EEC and then with various patchwork tuning solutions-provided no driveability joy and cost Mark at least one short-block meltdown. It wasn't until he swallowed hard and anted up for a Fuel Air Spark Technology EFI setup that the turbos and small-block settled into a peaceful and smooth working relationship.

This is a street/show car, not a drag racer, so Mark-mindful of his near-stock short-block-is quite content to restrain boost to a reasonable 10-psi level, the result being 550 hp at the wheels. But those wheels were having no end of trouble planting said power, leading Mark on a search for traction. "When the '03 Cobras came out, which could fit a 315 drag radial underneath 'em, I kinda got jealous," he explains, since his and other Fox cars couldn't swallow anywhere near that much rear tire. So he rolled the car into his family's shop, temporarily stripped out the interior, and commenced fabrication of a set of mini-tubs that would allow fitment of 315/35R17 rubber while still appearing virtually stock inside and out.

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With tubs in place, he had nowhere to mount shocks. Back he went to Miller Race Cars, where an inside-the-subframe-rail shock crossmember setup was engineered and fitted with QA1 coilovers. The factory control-arm pickup points are unchanged, with Steeda double-adjustable upper and lower arms installed. The stock fuel tank also remains and there is no protrusion of chassis related hardware into the interior. MRC also fabricated an adjustable antiroll bar to span beneath the Strange 9-inch axle assembly. Traction is now much less of a problem, and Mark was careful to keep rear-wheel offsets such that a stock appearance is maintained. Sneaky bugger.

With all that grip, Mark is pondering substitution of a D.S.S. 331 short-block to safely allow unleashing more of the turbo twin's untapped boost potential, and he keeps thinking about the potential tuning advantages of FAST's faster and even more street-friendly new XFI engine-management system. So it's eight years and running, but as Mark points out, "It's never done."